Van Gaal admits Memphis Depay has failed to impress

Manchester United manager Louis van Gaal has conceded that Memphis Depay has not lived up to expectations since his £25m move to Old Trafford

Depay has been left out of the United starting line-up in recent weeks due to a lack of form, but with Wayne Rooney, Anthony Martial and Marouane Fellaini unavailable, Van Gaal could ask Depay to lead the line for United at Watford on Saturday.

Earlier this summer, Van Gaal hailed Depay as the "greatest talent of his age", but the Dutch forward has looked nothing like the man who topped the Eredivisie scoring charts with 22 goals for PSV Eindhoven last season.

When asked if he expected more of his compatriot, Van Gaal said: "Of course, because otherwise he was still in the team.

"Otherwise I don't look for another solution and (that is why) I have kept Jesse Lingard and Andreas Pereira, for that option."

Depay's confident persona is said to have not gone down well with some at United, but Van Gaal insists the forward is applying himself correctly in training.

"Now he has to fight back and he does it, so I am satisfied (with him)," Van Gaal said.

"There is always a chance (he will play on Saturday). I have to see and compare players. "He is always looking very good.

"Jesse Lingard has played very well, but it's a question if he is consistent and that we have to wait and see.

"I don't have any problems with players but sometimes they are out of the team because their competitor is in that moment in a better shape but that doesn't mean that I have a quarrel with the player. It's a matter of form."

Six players will miss United's trip to Watford on Saturday lunchtime. Martial is suffering from a foot injury he sustained against England on Tuesday, but could be back for next Wednesday's Champions League game against PSV.

Rooney will also miss the trip to Vicarage Road through illness. With Fellaini still sidelined by a calf problem, Van Gaal admits he has a "big problem" selecting an attack for Saturday.

The inexperienced James Wilson, who has started just two league games under Van Gaal, is lacking match fitness following an injury.

Fellaini would have started up front had he recovered from the calf problem that ruled him out of international duty.

"Fellaini is injured and that's a big blow because Rooney is ill, so we have a big problem, I think," Van Gaal said.

"It was a big surprise because I thought Fellaini (would have) recovered after the international break."

United do not have the option to recall Adnan Januzaj from his loan at Borussia Dortmund, Van Gaal revealed.

"I don't think that (he can come back in January)," Van Gaal said of the Belgium forward.

It came as something of a surprise when Januzaj joined Dortmund on loan in August.

The 20-year-old was expected to challenge for a first-team place at Old Trafford, but Van Gaal loaned him to the Germans on deadline day.

Januzaj has only started two league games for the club and Van Gaal admitted the forward was taking a risk by moving to Dortmund.

"In a club like Borussia Dortmund, all the players there are also of a certain level and I said in advance: 'that's a big risk for you because you have to compete with other players of a higher level' and that is not so easy," Van Gaal said.

"It's the same thing as in Manchester United. He has to compete with higher level players and I want him to play all the matches and that is why I want to play him also in the Premier League but he chose for Borussia Dortmund."

Antonio Valencia (foot), Luke Shaw (leg) and Michael Carrick, who hurt his ankle playing for England in Spain, are out.

Van Gaal will check whether Morgan Schneiderlin and Bastian Schweinsteiger, who were playing at the Stade de France last Friday when the Paris terrorist attacks occurred, are ready to feature at Watford.

He said: "It's a question if the players want to play. I always look in the players' eyes after training and make my decision."